/*
 *   Copyright 1999-2018 dragonshard.net.
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *        http://www.apache.org/licenses/LICENSE-2.0
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package net.dragonshard.dsf.web.core.framework.modelmapper.jsr310;

import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.time.temporal.Temporal;
import java.util.Calendar;
import java.util.Date;
import org.modelmapper.Converter;
import org.modelmapper.internal.Errors;
import org.modelmapper.spi.ConditionalConverter;
import org.modelmapper.spi.MappingContext;

/**
 * Converts  {@link Object} to {@link Temporal}
 *
 * @author Chun Han Hsiao
 */
public class ToTemporalConverter implements ConditionalConverter<Object, Temporal> {

  private final Jsr310ModuleConfig config;
  private final LocalDateTimeConverter localDateTimeConverter = new LocalDateTimeConverter();
  private final LocalDateConverter localDateConverter = new LocalDateConverter();
  private final InstantConverter instantConverter = new InstantConverter();

  public ToTemporalConverter(Jsr310ModuleConfig config) {
    this.config = config;
  }

  @Override
  public MatchResult match(Class<?> sourceType, Class<?> destinationType) {
    return Temporal.class.isAssignableFrom(destinationType)
      ? MatchResult.FULL : MatchResult.NONE;
  }

  @Override
  public Temporal convert(MappingContext<Object, Temporal> mappingContext) {
    Class<?> destinationType = mappingContext.getDestinationType();
    if (LocalDateTime.class.equals(destinationType)) {
      return localDateTimeConverter.convert(mappingContext);
    } else if (LocalDate.class.equals(destinationType)) {
      return localDateConverter.convert(mappingContext);
    } else if (Instant.class.equals(destinationType)) {
      return instantConverter.convert(mappingContext);
    } else {
      throw new Errors().addMessage("Unsupported mapping types[%s->%s]",
        mappingContext.getSourceType().getName(), destinationType.getName())
        .toMappingException();
    }
  }

  private class LocalDateTimeConverter implements Converter<Object, Temporal> {

    @Override
    public Temporal convert(MappingContext<Object, Temporal> mappingContext) {
      return convertLocalDateTime(mappingContext);
    }
  }

  private class LocalDateConverter implements Converter<Object, Temporal> {

    @Override
    public Temporal convert(MappingContext<Object, Temporal> mappingContext) {
      return convertLocalDate(mappingContext);
    }
  }

  private class InstantConverter implements Converter<Object, Temporal> {

    @Override
    public Temporal convert(MappingContext<Object, Temporal> mappingContext) {
      return convertInstant(mappingContext);
    }
  }

  private LocalDate convertLocalDate(MappingContext<?, ?> mappingContext) {
    Object source = mappingContext.getSource();
    Class<?> sourceType = source.getClass();
    if (sourceType.equals(String.class)) {
      return LocalDate.parse((String) source,
        DateTimeFormatter.ofPattern(config.getDatePattern()));
    }
    return convertInstant(mappingContext).atZone(config.getZoneId()).toLocalDate();
  }

  private LocalDateTime convertLocalDateTime(MappingContext<?, ?> mappingContext) {
    Object source = mappingContext.getSource();
    Class<?> sourceType = source.getClass();
    if (sourceType.equals(String.class)) {
      return LocalDateTime.parse((String) source,
        DateTimeFormatter.ofPattern(config.getDateTimePattern()));
    }
    return convertInstant(mappingContext).atZone(config.getZoneId()).toLocalDateTime();
  }

  private Instant convertInstant(MappingContext<?, ?> mappingContext) {
    Object source = mappingContext.getSource();
    Class<?> sourceType = source.getClass();
    if (sourceType.equals(String.class)) {
      return LocalDateTime.parse((String) source,
        DateTimeFormatter.ofPattern(config.getDateTimePattern()))
        .atZone(config.getZoneId()).toInstant();
    } else if (Date.class.isAssignableFrom(sourceType)) {
      return Instant.ofEpochMilli(((Date) source).getTime());
    } else if (Calendar.class.isAssignableFrom(sourceType)) {
      return Instant.ofEpochMilli(((Calendar) source).getTime().getTime());
    } else if (Number.class.isAssignableFrom(sourceType)) {
      return Instant.ofEpochMilli(((Number) source).longValue());
    } else {
      throw new Errors().addMessage("Unsupported mapping types[%s->%s]",
        sourceType.getName(), mappingContext.getDestinationType().getName())
        .toMappingException();
    }
  }
}
